This invention relates to the regulated power supply art and, more particularly, to the aspect of the art in which a plurality of power supplies are operated in parallel to obtain a predetermined current capacity.
According to the prior art, when a plurality of similar power supplies are disposed in parallel, it has been necessary to establish a master-slave relationship between their respective regulators. The master supply operates in a completely normal fashion and may be set up for either constant voltage or constant current as required. The slave supply employs its regulator circuit to compare the voltage drop across the current monitoring resistor of the master supply with the voltage drop across the current monitoring resistor of the slave supply. The slave regulator adjusts the conduction of the series regulator in the slave supply so that the IR drops across the two current monitoring resistors are held equal. Therefore, assuming equal values of current monitoring resistors in the master and slave supplies, the output current contribution will always be equal regardless of the output voltage or current requirement of the load.
Those skilled in the art will understand that the regulators associated with master and slave supplies must physically differ and will recognize the advantages that would accrue from the realization of a power supply which can be disposed in parallel with one or more identical supplies. No internal changes would be necessary to convert a supply to the slave configuration nor would dedicated external wiring have to be provided. Capability for expansion of the power supply systems to a higher current capacity would be greatly simplified.
It is therefore a broad object of our invention to provide an improved regulated power supply system.
It is another object of our invention to provide such an improved system in which a plurality of power supplies are employed.
It is a more specific object of our invention to provide such an improved system in which all the power supplies are identical.